A physiologically accurate mechanical representation of a retrograde nail-bone construct under walking load

Intramedullary (IM) nails have become a viable alternative in bone-distraction operationsand treatments of long bone fractures. Upon stabilization of the fractured/dissected limb viathe nail, the resulting construct accommodates the load bearing function of the otherwisehealthy limb. In establishing design performance targets for these devices, in vitro testconditions are widely accepted leaving the in vivo conditions aside. However, in vivo devicefailures reported in both lengthening and fracture healing periods necessitate novel modelingconsiderations. In this thesis, it was aimed to identify mechanical conditions which IM nailsare exposed to during distinct operational stages, and to predict the mechanical response ofthese devices more accurately in a finite element environment. In this regard, loads arisingin limb distraction (SFM) was simulated in the first part of the study, as this brings the bone-implant construct to a totally different regime than the hip-joint contact force (PFM). Theeffect of loading type on load transmission paths through the locking pins was comparedfor two distinct loading modes, namely, SFM and PFM. In the second part of the thesis,the response of retrograde type intramedullary nail-implanted femur with a diaphyseal mid-fracture as well as the intact femur were investigated at the instance of maximum hip contactforce of a gait cycle. The effect of different boundary and loading configurations on themechanical behavior of the construct were identified.